is this enough power

[britishninja]

im going to run a 72 volt system with a D&D ES 15-6 motor and a 500 amp controller and im planing to get 24 6v 12 amp batteries and hook groups of 2 to get 24 amps out of a pack giving me a total of 288 amps how long of a ride time will that give me and is their some site i can use to calculate this
thanks

 

[landuse]

Hey there. I am sorry I cannot help, but someone else will chip in soon

 

[jman231994]

Technically the whole setup will still only be 24 Ah. I had a quick look into that motor but didnt come up with anything....I'll look again. That motor seems rather powerful though and would likely draw a lot of current

EDIT: From what I've been reading that motor can peak up to around what your saying your controller is rated for. That should be fine, however you must realise how short the run time will be for this. Lets say the motor is only consuming 100A, (which seems to be incredibly low and optimistic for that motor), the batteries would be depleted in less than one quarter of an hour. What do you intend on using this on?

 

[Fimka]

Hi,

i also have a question which is related to the original. whats the math/calculation behind figuring out how much power the motor will draw from the batteries based on the currest setup. what factors should be considered (eg. weight, RPMs, etc.)

As an example my current setup:
Motor: 36v, 500w, 3000 rpms max
Controller: 36v, 500w, 30amps
Kart weight: 100lbs
Rider weight: 180lbs

Also, is there a way to figure out how much the motor will take, if i reduce the gearing form 6:1 to 4:1 what's the math in figuring out if your engine/controller will be able to take it

Any help is appreciated

Thanks

 

[britishninja]

1st how would the whole set up only give me 24 amps
2nd what would you suggest i do for power then and if you could keep the system with the 24 6v batteries that would be great

 

[jman231994]

1st how would the whole set up only give me 24 amps

If I read it right your going to group the batteries in pairs, each pair will give you 6v and 24aH if wired in parallel. Then you will wire all the pairs together in series to give 72V. Your capacity wont increase when in series. Your voltage will, so youll still only have 24aH but 72V. This site explains it with diagrams.

http://www.zbattery.com/Connecting-Batteries-in-Series-or-Parallel

2nd what would you suggest i do for power then and if you could keep the system with the 24 6v batteries that would be great

Thats a tough question, realistically you cant get that much more out of it doing it other ways. Maybe reducing it down to 48v with the same batteries and going for more capacity could work, but, a motor draws less current at higher voltages so it may end up negating itself. It's really a tough thing to work out but I'll think about it and get back to you if I come up with anything good

 

[jman231994]

Hi,

i also have a question which is related to the original. whats the math/calculation behind figuring out how much power the motor will draw from the batteries based on the currest setup. what factors should be considered (eg. weight, RPMs, etc.)

As an example my current setup:
Motor: 36v, 500w, 3000 rpms max
Controller: 36v, 500w, 30amps
Kart weight: 100lbs
Rider weight: 180lbs

Also, is there a way to figure out how much the motor will take, if i reduce the gearing form 6:1 to 4:1 what's the math in figuring out if your engine/controller will be able to take it

Any help is appreciated

Thanks

You'd might as well make a new thread for it. That way this one wont get confusing working with two different scenario's. I'll try to help you out a bit later. Got to go out

EDIT: Ok, back. I'll only give you a bit of info here, make another thread and ill go into depth there about it, your question is much broader than the one on here. One thing I have to say if you cant be stuffed making another thread is this, P=IV, so Power in watts, is equal to Current in Amps X Voltage in....Volts lol. So a 500w motor running at 36v will consume 13.89 Amps. Odds are it will peak much higher though

 

[britishninja]

ok thanks i think ill make it 48v just 1 more question what type of charger should i get preferably one that will take care off them all at once

 

[jman231994]

ok thanks i think ill make it 48v just 1 more question what type of charger should i get preferably one that will take care off them all at once

Just an SLA charger, same as a car battery charger. You could get a 48v charger and charge them all together. But I think you will find it heaps cheaper to get two 24v chargers and have the batteries split into 2 sections when charging. We got a good one at school to charge our electric bike, but I cant remember where from or what brand it is. I'll have a look tomorrow and get back to you.

 

[britishninja]

Hey i found these batteries would they be good to use http://www.petra.com/stinger-spv20-power-series-300-amp-battery.html

 

[jman231994]

Hey i found these batteries would they be good to use http://www.petra.com/stinger-spv20-power-series-300-amp-battery.html

Sorry I forgot to look at that charger. Those batteries are still only 20aH. What you are looking for is a high amp-hour rating. The 300amp rating of those batteries means they can pump out 300amps over a short period of time. It has nothing to do with their capacity. I'm not sure where you live so I figured since most people on here are in the US I'd check out ebay haha. Found these

http://www.ebay.com/itm/35AH-12OLTV...US_Rechargeable_Batteries&hash=item27c83d4317

So for 48v 35aH you would need four of them wired in series. Just dont forget about weight, if you have a powerful motor it shouldnt be an issue though.